1. Field of the Invention
The present invention relates to a method for the activation of a mine possessing a specified radius of activation; in particular, an anti-helicopter mine, whereby the mine is placed into an alarm or waking condition through the intermediary of acoustic signals.
2. Discussion of the Prior Art
The disclosure of German Laid-Open Patent Appln. 38 37 483 A1, which is assigned to the common assignee of this application, is directed to a mine having an active charge, which is orientable against a target by means of a tracking unit; especially against a slow-flying target, and which is actuatable by an acquisition-sensor circuit. This mine possesses an alarm sensor circuit which acoustically monitors a spatial angular sector. Moreover, this known mine incorporates an infra-red bearing sensor circuit which detects a target entering into the above-mentioned spatial angular sector with regard to its type, location and path of movement. For the operation of the tracking unit and for the operation of the mentioned circuits there is provided an energy supply which is uncoupled from the alarm-sensor circuit, the bearing sensor circuit and the tracking unit. The bearing sensor circuit couples the tracking unit to the energy supply only when there has been detected a suitable target traveling along a path which is suitable for the attacking thereof.
Copending U.S. patent appln. Ser. No. 07/889,455; filed on May 27, 1992, which is assigned to the common assignee of the present application, and the disclosure of which is incorporated herein by reference, discloses a sensor arrangement for an active body; in particular, for a land mine which is deployed against ground and airborne targets, including an alarm sensor which is responsive to the approach of a target, and incorporating circuit arrangement for the environmentally-adaptive setting of sensor-evaluating circuits for the release of the active mechanism for defending against or combatting the target. Hereby, at a low elevation above ground, there is provided at least one antenna for emitting an undirected electromagnetic ground wave and possibly also for receiving reflections of the environment upon the deployment of the active body; as well as, after activation by the alarm sensor, for determining the relative movement of a target which has penetrated into the previously encompassed environment or surroundings, on the basis of reflections from the target.
Copending U. S. patent appln. Ser. No. 07/891,392; filed May 29, 1992, which is assigned to the common assignee of this application, and the disclosure of which is incorporated herein by reference, describes a sensor arrangement for an active body; especially for a land mine deployed against ground and airborne targets, which includes an alarm sensor which is responsive to the approach of a target object, and with a memory storage for environmental or surroundings information obtained by means of a Non-Line of Sight radar (NLOS-radar). In that instance, in addition to the NLOS-radar which operates in a relatively low-frequency undirected mode with a range-dependently operating multiple-target extractor, there is provided a direction-finding or bearing base for obtaining directional information from the sensor arrangement to target objects. Hereby, there may be provided a plurality of high-frequency antennae or, in essence, a plurality of microphones as the target direction-finding or bearing base.
Further to the sensor arrangement as described hereinabove, pursuant to a further development in the above-mentioned sensor arrangement there is set forth in that U.S. patent application a concept in which the acoustic directional or bearing information should be as accurate as possible in order to again be able to derive therefrom range-finding or distance information. This is achieved with the foregoing arrangement in that the active body is equipped with at least three microphones, which in order to achieve a base configuration which is relatively large-in comparison with the base of the active body, are spaced from the active body, whereby one of the microphones can be located on the active body and the remaining microphones remain at all times connected to the active body.